1. Field of the Invention
The present invention relates to a sheet supply cassette for storing sheets therein and an image forming apparatus of an electrophographic type including the sheet supply cassette.
2. Description of the Related Art
As a sheet supply cassette for use in an image forming apparatus, there is known a sheet supply cassette which includes a main frame body and an auxiliary frame body slidably disposed on the main frame body, while the auxiliary frame body can be made to expand and contract according to the size of sheets to be stored (see JP-A-5-51136). And, there is also known a sheet residual quantity-mechanism which detects the residual quantity of sheets in the sheet supply cassette to display the sheet residual quantity in the sheet supply cassette (see JP-A-6-271141 and JP-A-10-194479).
However, conventionally, there is not known a technique in which a sheet residual quantity display mechanism is applied to an expandable and contractible sheet supply cassette. Since the conventional sheet residual quantity display mechanism is structured such that it moves a residual quantity display portion connected to a sheet placement plate for placing sheets thereon, in case where this mechanism is applied to a sheet supply cassette which is structured so as to be expandable and contractible, the sheet residual quantity display portion must be disposed on a main frame body on which the sheet placement plate is disposed. In case where a sheet supply cassette is mounted on an image forming apparatus, when the auxiliary frame body is situated on the front surface side and the main frame body is situated on the deep side, the structure including the sheet residual quantity display portion on the main frame body raises a problem that a user is hard to see the sheet residual quantity display portion to make it difficult to confirm the sheet residual quantity.